The identification and imaging of objects by use of radiation systems is widespread, examples of which are marine sonars, microwave antennas, and medical ultrasound or magnetic resonance imagers; and uses of which include feature based navigation, object recognition and object imaging, coherent (full wave) correlation, coherent mosaicking, bathymetry, computed tomography, etc. Each suffers from the defect that detection of a radiative signal from a given point is aperture shape dependent, making signal correlation and image coherence problematic. Such variation in aperture shape is particularly felt in synthetic aperture systems, such as SAR or SAS.
An allied problem is that of a radiation sensor (e.g. radar or sonar) having curvature discontinuities, such as a sensor formed of a number of small, flat, segments disposed along an overall curve, or gaps between segments. Curvature of the sensor is discontinuous where individual segments join, or gaps lie, which distorts the image, if the image is not properly weighted.